Earth 0 (real world): Ordinary human society in the 21st century. The protagonist Lin Chen is a sophomore computer science student and an ashes veteran player of the "Rock Kingdom" web game.
Kalosia Continent (Game World): A real parallel world developed by Rubik's Cube Company using "parallel universe projection technology" as game material. In the Rubik's Cube Company's system description, Carosia is characterized as "an imaginary world based on magical civilization - Locke Continent. Here, humans and elves are not master-servant relationships, but symbiotic partners who coexist peacefully based on the spirit of contract."
Nightmare Realm (Dark Dimension): The realm of chaos that exists between the two worlds and is the source of all dark forces.
